From 5966a68a64e193a924c62364a2ef93a19cc3dccd Mon Sep 17 00:00:00 2001
From: Yuri Sizov <yuris@humnom.net>
Date: Sat, 28 Sep 2024 16:35:26 +0200
Subject: [PATCH] Better control access to the next element in SLL

This is a part of a rework that should make it
safer to use and properly managed.

The next pointer is no longer public. Instead a
getter was introduced for reading, and several
specialized setters were introduced for writing.
---
 src/chip/channels/siopm_channel_base.cpp      | 10 +--
 src/chip/channels/siopm_channel_fm.cpp        | 72 +++++++++----------
 src/chip/channels/siopm_channel_ks.cpp        |  2 +-
 src/chip/channels/siopm_channel_pcm.cpp       | 30 ++++----
 src/chip/siopm_stream.cpp                     | 12 ++--
 src/chip/wave/siopm_wave_sampler_data.cpp     |  4 +-
 src/effector/effects/si_effect_autopan.cpp    | 12 ++--
 src/effector/effects/si_effect_compressor.cpp |  2 +-
 .../filters/si_controllable_filter_base.cpp   |  8 +--
 src/sequencer/base/mml_executor.cpp           |  6 +-
 src/sequencer/simml_envelope_table.cpp        | 16 ++---
 src/sequencer/simml_track.cpp                 | 18 ++---
 src/sion_driver.cpp                           |  4 +-
 src/templates/singly_linked_list.h            | 54 +++++++++-----
 src/utils/translator_util.cpp                 | 22 +++---
 15 files changed, 143 insertions(+), 129 deletions(-)

diff --git a/src/chip/channels/siopm_channel_base.cpp b/src/chip/channels/siopm_channel_base.cpp
index a13b0f1..50ff168 100644
--- a/src/chip/channels/siopm_channel_base.cpp
+++ b/src/chip/channels/siopm_channel_base.cpp
@@ -264,7 +264,7 @@ void SiOPMChannelBase::note_off() {
 SinglyLinkedList<int> *SiOPMChannelBase::_rotate_pipe(SinglyLinkedList<int> *p_pipe, int p_length) {
 	SinglyLinkedList<int> *pipe = p_pipe;
 	for (int i = 0; i < p_length; i++) {
-		pipe = pipe->next;
+		pipe = pipe->next();
 	}
 	return pipe;
 }
@@ -302,8 +302,8 @@ void SiOPMChannelBase::_apply_ring_modulation(SinglyLinkedList<int> *p_target, i
 
 	for (int i = 0; i < p_length; i++) {
 		target->value *= pipe->value * _ringmod_level;
-		pipe = pipe->next;
-		target = target->next;
+		pipe = pipe->next();
+		target = target->next();
 	}
 
 	_ring_pipe = pipe;
@@ -327,7 +327,7 @@ void SiOPMChannelBase::_apply_sv_filter(SinglyLinkedList<int> *p_target, int p_l
 			r_variables[0] += r_variables[1] * cutoff_value;
 
 			target->value = (int)r_variables[_filter_type];
-			target = target->next;
+			target = target->next();
 		}
 		length -= step;
 
@@ -352,7 +352,7 @@ void SiOPMChannelBase::_apply_sv_filter(SinglyLinkedList<int> *p_target, int p_l
 		r_variables[0] += r_variables[1] * cutoff_value;
 
 		target->value = (int)r_variables[_filter_type];
-		target = target->next;
+		target = target->next();
 	}
 
 	// Next setting.
diff --git a/src/chip/channels/siopm_channel_fm.cpp b/src/chip/channels/siopm_channel_fm.cpp
index 99b00d6..9f18d3d 100644
--- a/src/chip/channels/siopm_channel_fm.cpp
+++ b/src/chip/channels/siopm_channel_fm.cpp
@@ -818,9 +818,9 @@ void SiOPMChannelFM::_process_operator1_lfo_off(int p_length) {
 		{
 			out_pipe->value = output + base_pipe->value;
 
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -860,9 +860,9 @@ void SiOPMChannelFM::_process_operator1_lfo_on(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -927,9 +927,9 @@ void SiOPMChannelFM::_process_operator2(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = _pipe0->value + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1016,9 +1016,9 @@ void SiOPMChannelFM::_process_operator3(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = _pipe0->value + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1125,9 +1125,9 @@ void SiOPMChannelFM::_process_operator4(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = _pipe0->value + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1162,9 +1162,9 @@ void SiOPMChannelFM::_process_pcm_lfo_off(int p_length) {
 					// Fast forward.
 					for (; i < p_length; i++) {
 						out_pipe->value = base_pipe->value;
-						in_pipe = in_pipe->next;
-						base_pipe = base_pipe->next;
-						out_pipe = out_pipe->next;
+						in_pipe = in_pipe->next();
+						base_pipe = base_pipe->next();
+						out_pipe = out_pipe->next();
 					}
 					break;
 				} else {
@@ -1184,9 +1184,9 @@ void SiOPMChannelFM::_process_pcm_lfo_off(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1224,9 +1224,9 @@ void SiOPMChannelFM::_process_pcm_lfo_on(int p_length) {
 					// Fast forward.
 					for (; i < p_length; i++) {
 						out_pipe->value = base_pipe->value;
-						in_pipe = in_pipe->next;
-						base_pipe = base_pipe->next;
-						out_pipe = out_pipe->next;
+						in_pipe = in_pipe->next();
+						base_pipe = base_pipe->next();
+						out_pipe = out_pipe->next();
 					}
 					break;
 				} else {
@@ -1246,9 +1246,9 @@ void SiOPMChannelFM::_process_pcm_lfo_on(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1304,9 +1304,9 @@ void SiOPMChannelFM::_process_analog_like(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output0 + output1 + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1360,9 +1360,9 @@ void SiOPMChannelFM::_process_ring(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
@@ -1417,9 +1417,9 @@ void SiOPMChannelFM::_process_sync(int p_length) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			in_pipe = in_pipe->next;
-			base_pipe = base_pipe->next;
-			out_pipe = out_pipe->next;
+			in_pipe = in_pipe->next();
+			base_pipe = base_pipe->next();
+			out_pipe = out_pipe->next();
 		}
 	}
 
diff --git a/src/chip/channels/siopm_channel_ks.cpp b/src/chip/channels/siopm_channel_ks.cpp
index aaf8d27..297e87b 100644
--- a/src/chip/channels/siopm_channel_ks.cpp
+++ b/src/chip/channels/siopm_channel_ks.cpp
@@ -167,7 +167,7 @@ void SiOPMChannelKS::_apply_karplus_strong(SinglyLinkedList<int> *p_target, int
 
 		_ks_delay_buffer.write[buffer_index] = _output;
 		target->value = (int)_output;
-		target = target->next;
+		target = target->next();
 	}
 }
 
diff --git a/src/chip/channels/siopm_channel_pcm.cpp b/src/chip/channels/siopm_channel_pcm.cpp
index f2f1b93..9f0ecef 100644
--- a/src/chip/channels/siopm_channel_pcm.cpp
+++ b/src/chip/channels/siopm_channel_pcm.cpp
@@ -304,8 +304,8 @@ void SiOPMChannelPCM::_process_operator_mono(int p_length, bool p_mix) {
 	if (_operator->get_pcm_end_point() <= 0) {
 		for (int i = 0; i < p_length; i++) {
 			out_pipe->value = base_pipe->value;
-			out_pipe = out_pipe->next;
-			base_pipe = base_pipe->next;
+			out_pipe = out_pipe->next();
+			base_pipe = base_pipe->next();
 		}
 
 		_out_pipe = out_pipe;
@@ -337,7 +337,7 @@ void SiOPMChannelPCM::_process_operator_mono(int p_length, bool p_mix) {
 					// Fast forward.
 					for (; i < p_length; i++) {
 						out_pipe->value = 0;
-						out_pipe = out_pipe->next;
+						out_pipe = out_pipe->next();
 					}
 					break;
 				} else {
@@ -355,8 +355,8 @@ void SiOPMChannelPCM::_process_operator_mono(int p_length, bool p_mix) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output + base_pipe->value;
-			out_pipe = out_pipe->next;
-			base_pipe = base_pipe->next;
+			out_pipe = out_pipe->next();
+			base_pipe = base_pipe->next();
 		}
 	}
 
@@ -373,12 +373,12 @@ void SiOPMChannelPCM::_process_operator_stereo(int p_length, bool p_mix) {
 	if (_operator->get_pcm_end_point() <= 0) {
 		for (int i = 0; i < p_length; i++) {
 			out_pipe->value = base_pipe->value;
-			out_pipe = out_pipe->next;
-			base_pipe = base_pipe->next;
+			out_pipe = out_pipe->next();
+			base_pipe = base_pipe->next();
 
 			out_pipe2->value = base_pipe2->value;
-			out_pipe2 = out_pipe2->next;
-			base_pipe2 = base_pipe2->next;
+			out_pipe2 = out_pipe2->next();
+			base_pipe2 = base_pipe2->next();
 		}
 
 		_out_pipe = out_pipe;
@@ -412,9 +412,9 @@ void SiOPMChannelPCM::_process_operator_stereo(int p_length, bool p_mix) {
 					// Fast forward.
 					for (; i < p_length; i++) {
 						out_pipe->value = 0;
-						out_pipe = out_pipe->next;
+						out_pipe = out_pipe->next();
 						out_pipe2->value = 0;
-						out_pipe2 = out_pipe2->next;
+						out_pipe2 = out_pipe2->next();
 					}
 					break;
 				} else {
@@ -444,12 +444,12 @@ void SiOPMChannelPCM::_process_operator_stereo(int p_length, bool p_mix) {
 		// Output and increment pointers.
 		{
 			out_pipe->value = output_left + base_pipe->value;
-			out_pipe = out_pipe->next;
-			base_pipe = base_pipe->next;
+			out_pipe = out_pipe->next();
+			base_pipe = base_pipe->next();
 
 			out_pipe2->value = output_right + base_pipe2->value;
-			out_pipe2 = out_pipe2->next;
-			base_pipe2 = base_pipe2->next;
+			out_pipe2 = out_pipe2->next();
+			base_pipe2 = base_pipe2->next();
 		}
 	}
 
diff --git a/src/chip/siopm_stream.cpp b/src/chip/siopm_stream.cpp
index 61fd41b..70535ef 100644
--- a/src/chip/siopm_stream.cpp
+++ b/src/chip/siopm_stream.cpp
@@ -50,7 +50,7 @@ void SiOPMStream::write(SinglyLinkedList<int> *p_data, int p_start, int p_length
 			buffer.write[i] += current->value * volume_right;
 			i++;
 
-			current = current->next;
+			current = current->next();
 		}
 	} else if (channels == 1) { // mono
 		SinglyLinkedList<int> *current = p_data;
@@ -60,7 +60,7 @@ void SiOPMStream::write(SinglyLinkedList<int> *p_data, int p_start, int p_length
 			buffer.write[i] += current->value * volume;
 			i++;
 
-			current = current->next;
+			current = current->next();
 		}
 	}
 }
@@ -83,8 +83,8 @@ void SiOPMStream::write_stereo(SinglyLinkedList<int> *p_left, SinglyLinkedList<i
 			buffer.write[i] += current_right->value * volume_right;
 			i++;
 
-			current_left = current_left->next;
-			current_right = current_right->next;
+			current_left = current_left->next();
+			current_right = current_right->next();
 		}
 	} else if (channels == 1) { // mono
 		volume *= 0.5;
@@ -98,8 +98,8 @@ void SiOPMStream::write_stereo(SinglyLinkedList<int> *p_left, SinglyLinkedList<i
 			buffer.write[i] += (current_left->value + current_right->value) * volume;
 			i++;
 
-			current_left = current_left->next;
-			current_right = current_right->next;
+			current_left = current_left->next();
+			current_right = current_right->next();
 		}
 	}
 }
diff --git a/src/chip/wave/siopm_wave_sampler_data.cpp b/src/chip/wave/siopm_wave_sampler_data.cpp
index 6ee345d..f694177 100644
--- a/src/chip/wave/siopm_wave_sampler_data.cpp
+++ b/src/chip/wave/siopm_wave_sampler_data.cpp
@@ -45,7 +45,7 @@ int SiOPMWaveSamplerData::_seek_head_silence() {
 		for (; i < _wave_data.size(); i++) {
 			ms -= ms_window->value;
 
-			ms_window = ms_window->next;
+			ms_window = ms_window->next();
 			ms_window->value = _wave_data[i] * _wave_data[i];
 			ms += ms_window->value;
 
@@ -64,7 +64,7 @@ int SiOPMWaveSamplerData::_seek_head_silence() {
 			// Here we would increment and then break. This is inconsistent and needs to be validated.
 			// Keeping as in the original implementation for now.
 
-			ms_window = ms_window->next;
+			ms_window = ms_window->next();
 			ms_window->value = _wave_data[i] * _wave_data[i];
 			i++;
 			ms_window->value += _wave_data[i] * _wave_data[i];
diff --git a/src/effector/effects/si_effect_autopan.cpp b/src/effector/effects/si_effect_autopan.cpp
index bd8a797..29019cd 100644
--- a/src/effector/effects/si_effect_autopan.cpp
+++ b/src/effector/effects/si_effect_autopan.cpp
@@ -23,13 +23,13 @@ void SiEffectAutopan::set_params(double p_frequency, double p_stereo_width) {
 	// Volume table.
 	for (int i = -128; i < 128; i++) {
 		_p_left->value = Math::sin(1.5707963267948965 + i * width);
-		_p_left = _p_left->next;
+		_p_left = _p_left->next();
 	}
 
 	// Right phase shift.
 	_p_right = _p_left;
 	for (int i = 0; i < 128; i++) {
-		_p_right = _p_right->next;
+		_p_right = _p_right->next();
 	}
 }
 
@@ -45,8 +45,8 @@ void SiEffectAutopan::_process_lfo_mono(Vector<double> *r_buffer, int p_start_in
 		r_buffer->write[i + 1] = value * _p_right->value;
 	}
 
-	_p_left = _p_left->next;
-	_p_right = _p_right->next;
+	_p_left = _p_left->next();
+	_p_right = _p_right->next();
 }
 
 void SiEffectAutopan::_process_lfo_stereo(Vector<double> *r_buffer, int p_start_index, int p_length) {
@@ -58,8 +58,8 @@ void SiEffectAutopan::_process_lfo_stereo(Vector<double> *r_buffer, int p_start_
 		r_buffer->write[i + 1] = value_left * _p_right->value + value_right * _p_left->value;
 	}
 
-	_p_left = _p_left->next;
-	_p_right = _p_right->next;
+	_p_left = _p_left->next();
+	_p_right = _p_right->next();
 }
 
 int SiEffectAutopan::process(int p_channels, Vector<double> *r_buffer, int p_start_index, int p_length) {
diff --git a/src/effector/effects/si_effect_compressor.cpp b/src/effector/effects/si_effect_compressor.cpp
index 0aead52..a0329d3 100644
--- a/src/effector/effects/si_effect_compressor.cpp
+++ b/src/effector/effects/si_effect_compressor.cpp
@@ -45,7 +45,7 @@ int SiEffectCompressor::process(int p_channels, Vector<double> *r_buffer, int p_
 		double value_left = (*r_buffer)[i];
 		double value_right = (*r_buffer)[i + 1];
 
-		_window_rms_list = _window_rms_list->next;
+		_window_rms_list = _window_rms_list->next();
 		_window_rms_total -= _window_rms_list->value;
 		_window_rms_list->value = value_left * value_left + value_right * value_right;
 		_window_rms_total += _window_rms_list->value;
diff --git a/src/effector/filters/si_controllable_filter_base.cpp b/src/effector/filters/si_controllable_filter_base.cpp
index 05a9d18..83869a6 100644
--- a/src/effector/filters/si_controllable_filter_base.cpp
+++ b/src/effector/filters/si_controllable_filter_base.cpp
@@ -83,12 +83,12 @@ int SiControllableFilterBase::process(int p_channels, Vector<double> *r_buffer,
 		_process_lfo(r_buffer, i, step);
 
 		if (_cutoff_ptr) {
-			_cutoff_ptr = _cutoff_ptr->next;
+			_cutoff_ptr = _cutoff_ptr->next();
 			_cutoff_index = (_cutoff_ptr ? _cutoff_ptr->value : 128);
 		}
 
 		if (_resonance_ptr) {
-			_resonance_ptr = _resonance_ptr->next;
+			_resonance_ptr = _resonance_ptr->next();
 			_resonance = (_resonance_ptr ? _resonance_ptr->value * 0.007751937984496124 : 0);
 		}
 
@@ -132,8 +132,8 @@ SiControllableFilterBase::SiControllableFilterBase() :
 			inc_ptr->value = i;
 			dec_ptr->value = 128 - i;
 
-			inc_ptr = inc_ptr->next;
-			dec_ptr = dec_ptr->next;
+			inc_ptr = inc_ptr->next();
+			dec_ptr = dec_ptr->next();
 		}
 	}
 }
diff --git a/src/sequencer/base/mml_executor.cpp b/src/sequencer/base/mml_executor.cpp
index 8b73337..b0dcc37 100644
--- a/src/sequencer/base/mml_executor.cpp
+++ b/src/sequencer/base/mml_executor.cpp
@@ -126,7 +126,7 @@ MMLEvent *MMLExecutor::on_repeat_all(MMLEvent *p_event) {
 
 MMLEvent *MMLExecutor::on_repeat_begin(MMLEvent *p_event) {
 	SinglyLinkedList<int> *counter = SinglyLinkedList<int>::alloc(p_event->get_data());
-	counter->next = _repeat_counters;
+	counter->link(_repeat_counters);
 	_repeat_counters = counter;
 
 	return p_event->get_next();
@@ -134,7 +134,7 @@ MMLEvent *MMLExecutor::on_repeat_begin(MMLEvent *p_event) {
 
 MMLEvent *MMLExecutor::on_repeat_break(MMLEvent *p_event) {
 	if (_repeat_counters->value == 1) {
-		SinglyLinkedList<int> *counter = _repeat_counters->next;
+		SinglyLinkedList<int> *counter = _repeat_counters->next();
 		SinglyLinkedList<int>::free(_repeat_counters);
 		_repeat_counters = counter;
 
@@ -148,7 +148,7 @@ MMLEvent *MMLExecutor::on_repeat_break(MMLEvent *p_event) {
 MMLEvent *MMLExecutor::on_repeat_end(MMLEvent *p_event) {
 	_repeat_counters->value -= 1;
 	if (_repeat_counters->value == 0) {
-		SinglyLinkedList<int> *counter = _repeat_counters->next;
+		SinglyLinkedList<int> *counter = _repeat_counters->next();
 		SinglyLinkedList<int>::free(_repeat_counters);
 		_repeat_counters = counter;
 
diff --git a/src/sequencer/simml_envelope_table.cpp b/src/sequencer/simml_envelope_table.cpp
index 5d906b2..37b540b 100644
--- a/src/sequencer/simml_envelope_table.cpp
+++ b/src/sequencer/simml_envelope_table.cpp
@@ -23,7 +23,7 @@ void SiMMLEnvelopeTable::to_vector(int p_length, Vector<int> *r_destination, int
 		int value = 0;
 		if (current) {
 			value = current->value;
-			current = current->next;
+			current = current->next();
 		}
 
 		CLAMP(value, p_min, p_max);
@@ -40,10 +40,10 @@ void SiMMLEnvelopeTable::copy_from(const Ref<SiMMLEnvelopeTable> &p_source) {
 
 	SinglyLinkedList<int> *curr_source = p_source->head;
 	SinglyLinkedList<int> *curr_destination = nullptr;
-	for (; curr_source != p_source->tail; curr_source = curr_source->next) {
+	for (; curr_source != p_source->tail; curr_source = curr_source->next()) {
 		SinglyLinkedList<int> *sll_value = SinglyLinkedList<int>::alloc(curr_source->value);
 		if (curr_destination) {
-			curr_destination->next = sll_value;
+			curr_destination->link(sll_value);
 			curr_destination = sll_value;
 		} else {
 			head = sll_value;
@@ -57,14 +57,14 @@ void SiMMLEnvelopeTable::_initialize(SinglyLinkedList<int> *p_head, SinglyLinked
 	tail = p_tail;
 
 	// Looping last data.
-	if (tail->next == nullptr) {
-		tail->next = tail;
+	if (tail->next() == nullptr) {
+		tail->link(tail);
 	}
 }
 
 void SiMMLEnvelopeTable::free() {
 	if (head) {
-		tail->next = nullptr;
+		tail->unlink();
 		SinglyLinkedList<int>::free_list(head);
 
 		head = nullptr;
@@ -90,9 +90,9 @@ SiMMLEnvelopeTable::SiMMLEnvelopeTable(Vector<int> p_table, int p_loop_point) {
 		}
 
 		tail->value = p_table[i];
-		tail = tail->next;
+		tail = tail->next();
 	}
 
 	tail->value = p_table[i];
-	tail->next = loop;
+	tail->link(loop);
 }
diff --git a/src/sequencer/simml_track.cpp b/src/sequencer/simml_track.cpp
index dc204bf..31434e8 100644
--- a/src/sequencer/simml_track.cpp
+++ b/src/sequencer/simml_track.cpp
@@ -217,7 +217,7 @@ SinglyLinkedList<int> *SiMMLTrack::_make_modulation_table(int p_depth, int p_end
 	if (p_delay != 0) {
 		for (int i = 0; i < p_delay; i++) {
 			element->value = p_depth;
-			element = element->next;
+			element = element->next();
 		}
 	}
 
@@ -228,7 +228,7 @@ SinglyLinkedList<int> *SiMMLTrack::_make_modulation_table(int p_depth, int p_end
 		for (int i = 0; i < p_term; i++) {
 			element->value = depth >> FIXED_BITS;
 			depth += step;
-			element = element->next;
+			element = element->next();
 		}
 	}
 
@@ -534,7 +534,7 @@ int SiMMLTrack::_buffer_envelope(int p_length, int p_step) {
 			int expression = CLAMP(_envelope_exp_offset + _envelope_exp->value, 0, 128);
 			_channel->offset_volume(expression, _velocity);
 
-			_envelope_exp = _envelope_exp->next;
+			_envelope_exp = _envelope_exp->next();
 			_counter_exp = _max_counter_exp;
 		}
 
@@ -545,14 +545,14 @@ int SiMMLTrack::_buffer_envelope(int p_length, int p_step) {
 			if (_counter_pitch == 1) {
 				_counter_pitch--;
 
-				_envelope_pitch = _envelope_pitch->next;
+				_envelope_pitch = _envelope_pitch->next();
 				_counter_pitch = _max_counter_pitch;
 			}
 
 			if (_counter_note == 1) {
 				_counter_note--;
 
-				_envelope_note = _envelope_note->next;
+				_envelope_note = _envelope_note->next();
 				_counter_note = _max_counter_note;
 			}
 
@@ -572,7 +572,7 @@ int SiMMLTrack::_buffer_envelope(int p_length, int p_step) {
 
 			_channel->offset_filter(_envelope_filter->value);
 
-			_envelope_filter = _envelope_filter->next;
+			_envelope_filter = _envelope_filter->next();
 			_counter_filter = _max_counter_filter;
 		}
 
@@ -582,18 +582,18 @@ int SiMMLTrack::_buffer_envelope(int p_length, int p_step) {
 
 			_channel_settings->select_tone(this, _envelope_voice->value);
 
-			_envelope_voice = _envelope_voice->next;
+			_envelope_voice = _envelope_voice->next();
 			_counter_voice = _max_counter_voice;
 		}
 
 		// Update modulations.
 		if (_envelope_mod_amp) {
 			_channel->set_amplitude_modulation(_envelope_mod_amp->value);
-			_envelope_mod_amp =_envelope_mod_amp->next;
+			_envelope_mod_amp =_envelope_mod_amp->next();
 		}
 		if (_envelope_mod_pitch) {
 			_channel->set_pitch_modulation(_envelope_mod_pitch->value);
-			_envelope_mod_pitch = _envelope_mod_pitch->next;
+			_envelope_mod_pitch = _envelope_mod_pitch->next();
 		}
 
 		remaining_length -= current_step;
diff --git a/src/sion_driver.cpp b/src/sion_driver.cpp
index ff9db82..1d27ac0 100644
--- a/src/sion_driver.cpp
+++ b/src/sion_driver.cpp
@@ -447,7 +447,7 @@ void SiONDriver::_streaming() {
 	_performance_stats.total_processing_time -= _performance_stats.processing_time_data->value;
 	_performance_stats.processing_time_data->value = Time::get_singleton()->get_ticks_msec() - start_time;
 	_performance_stats.total_processing_time += _performance_stats.processing_time_data->value;
-	_performance_stats.processing_time_data = _performance_stats.processing_time_data->next;
+	_performance_stats.processing_time_data = _performance_stats.processing_time_data->next();
 	_performance_stats.average_processing_time = _performance_stats.total_processing_time * _performance_stats.total_processing_time_ratio;
 
 	// Write samples.
@@ -607,7 +607,7 @@ void SiONDriver::play(const Variant &p_data, bool p_reset_effector) {
 	_performance_stats.total_processing_time = 0;
 	for (int i = 0; i < TIME_AVERAGING_COUNT; i++) {
 		_performance_stats.processing_time_data->value = 0;
-		_performance_stats.processing_time_data = _performance_stats.processing_time_data->next;
+		_performance_stats.processing_time_data = _performance_stats.processing_time_data->next();
 	}
 
 	_is_paused = false;
diff --git a/src/templates/singly_linked_list.h b/src/templates/singly_linked_list.h
index 98ee57b..17433fe 100644
--- a/src/templates/singly_linked_list.h
+++ b/src/templates/singly_linked_list.h
@@ -26,20 +26,21 @@ class SinglyLinkedList {
 	// In other words, this is going to leak on exit, unless memory is properly managed.
 	static SinglyLinkedList<T> *_free_list;
 
+	SinglyLinkedList<T> *_next = nullptr;
+
 public:
 	// NOTE: Original code called it `i`. There is no special accessor, so we opt for a better public name.
 	T value = 0;
-	SinglyLinkedList<T> *next = nullptr;
 
 	static SinglyLinkedList<T> *alloc(int p_value = 0) {
 		SinglyLinkedList<T> *ret;
 
 		if (_free_list) {
 			ret = _free_list;
-			_free_list = _free_list->next;
+			_free_list = _free_list->_next;
 
 			ret->value = p_value;
-			ret->next = nullptr;
+			ret->_next = nullptr;
 		} else {
 			ret = memnew(SinglyLinkedList<T>(p_value));
 		}
@@ -52,8 +53,7 @@ class SinglyLinkedList {
 
 		SinglyLinkedList<T> *elem = ret;
 		for (int i = 1; i < p_size; i++) {
-			elem->next = alloc(p_default_value);
-			elem = elem->next;
+			elem = elem->append(p_default_value);
 		}
 
 		return ret;
@@ -64,10 +64,9 @@ class SinglyLinkedList {
 
 		SinglyLinkedList<T> *elem = ret;
 		for (int i = 1; i < p_size; i++) {
-			elem->next = alloc(p_default_value);
-			elem = elem->next;
+			elem = elem->append(p_default_value);
 		}
-		elem->next = ret;
+		elem->_next = ret;
 
 		return ret;
 	}
@@ -75,7 +74,7 @@ class SinglyLinkedList {
 	static void free(SinglyLinkedList<T> *p_first_element) {
 		// Append the current allocated free list and then assume its position.
 		// The argument MUST be the first element in any list, otherwise we leave bad pointers.
-		p_first_element->next = _free_list;
+		p_first_element->_next = _free_list;
 		_free_list = p_first_element;
 	}
 
@@ -86,12 +85,12 @@ class SinglyLinkedList {
 
 		// The argument MUST be the first element in any list, otherwise we leave bad pointers.
 		SinglyLinkedList<T> *elem = p_first_element;
-		while (elem->next) {
-			elem = elem->next;
+		while (elem->_next) {
+			elem = elem->_next;
 		}
 
 		// Append the current allocated free list and then assume its position.
-		elem->next = _free_list;
+		elem->_next = _free_list;
 		_free_list = p_first_element;
 	}
 
@@ -102,12 +101,12 @@ class SinglyLinkedList {
 
 		// The argument MUST be the first element in any list, otherwise we leave bad pointers.
 		SinglyLinkedList<T> *elem = p_first_element;
-		while (elem->next != p_first_element) {
-			elem = elem->next;
+		while (elem->_next != p_first_element) {
+			elem = elem->_next;
 		}
 
 		// Append the current allocated free list and then assume its position.
-		elem->next = _free_list;
+		elem->_next = _free_list;
 		_free_list = p_first_element;
 	}
 
@@ -120,16 +119,35 @@ class SinglyLinkedList {
 		List<SinglyLinkedList<T> *> pager;
 		pager.push_back(p_first_element);
 
-		SinglyLinkedList<T> *elem = p_first_element->next;
+		SinglyLinkedList<T> *elem = p_first_element->_next;
 		while (elem != p_first_element) {
 			pager.push_back(elem);
-			elem = elem->next;
+			elem = elem->_next;
 		}
 
 		return pager;
 	}
 
-	SinglyLinkedList(int p_value = 0) {
+	//
+
+	SinglyLinkedList<T> *next() const {
+		return _next;
+	}
+
+	SinglyLinkedList<T> *append(T p_value) {
+		_next = alloc(p_value);
+		return _next;
+	}
+
+	void link(SinglyLinkedList<T> *p_element) {
+		_next = p_element;
+	}
+
+	void unlink() {
+		_next = nullptr;
+	}
+
+	SinglyLinkedList(T p_value) {
 		value = p_value;
 	}
 };
diff --git a/src/utils/translator_util.cpp b/src/utils/translator_util.cpp
index 8071ff9..1f6e4df 100644
--- a/src/utils/translator_util.cpp
+++ b/src/utils/translator_util.cpp
@@ -1505,8 +1505,7 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 					value = (int)(value * postfix_coef + postfix_offset + 0.5);
 
 					for (int j = 0; j < postfix_size; j++) {
-						last->next = SinglyLinkedList<int>::alloc(value);
-						last = last->next;
+						last = last->append(value);
 					}
 					index += postfix_size;
 
@@ -1517,8 +1516,7 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 
 				for (int i = 0; i < inter_size && index < p_max_index; i++) {
 					for (int j = 0; j < postfix_size; j++) {
-						last->next = SinglyLinkedList<int>::alloc(value);
-						last = last->next;
+						last = last->append(value);
 					}
 					index += postfix_size;
 				}
@@ -1529,8 +1527,7 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 			value = (int)(value * postfix_coef + postfix_offset + 0.5);
 
 			for (int j = 0; j < postfix_size; j++) {
-				last->next = SinglyLinkedList<int>::alloc(value);
-				last = last->next;
+				last = last->append(value);
 			}
 			index++;
 		} else if (!parsed_number->get_string(5).is_empty()) {
@@ -1546,7 +1543,7 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 			} else {                   // End loop.
 				ERR_FAIL_COND_V_MSG(loop_stack.is_empty(), parsed_table, "Translator: Failed to parse provided MML table, loop data is invalid.");
 
-				loop_head = loop_stack.back()->get()->next;
+				loop_head = loop_stack.back()->get()->next();
 				loop_stack.pop_back();
 				ERR_FAIL_COND_V_MSG(!loop_head, parsed_table, "Translator: Failed to parse provided MML table, loop data is invalid.");
 
@@ -1556,9 +1553,8 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 					loop_count = parsed_number->get_string(6).to_int();
 				}
 				for (int j = loop_count; j > 0; j--) {
-					for (SinglyLinkedList<int> *l = loop_head; l != loop_tail->next; l = l->next) {
-						last->next = SinglyLinkedList<int>::alloc(l->value);
-						last = last->next;
+					for (SinglyLinkedList<int> *l = loop_head; l != loop_tail->next(); l = l->next()) {
+						last = last->append(l->value);
 					}
 				}
 			}
@@ -1568,10 +1564,10 @@ TranslatorUtil::MMLTableNumbers TranslatorUtil::parse_table_numbers(String p_tab
 	}
 
 	if (repeat) {
-		last->next = repeat->next;
+		last->link(repeat->next());
 	}
 
-	parsed_table.head = head->next;
+	parsed_table.head = head->next();
 	parsed_table.tail = last;
 	parsed_table.length = index;
 	parsed_table.repeated = (repeat != nullptr);
@@ -1593,7 +1589,7 @@ void TranslatorUtil::parse_wav(String p_table_numbers, String p_postfix, Vector<
 		double value = (value_base->value + 0.5) * 0.0078125;
 		r_data->write[i] = CLAMP(value, -1, 1);
 
-		value_base = value_base->next;
+		value_base = value_base->next();
 	}
 
 	for (; i < data_length; i++) {